Figure 1

Radiation dose response analysis in mouse CRIH model. (A) The dose response curve experimental timeline with mice exposed to 0, 2, 5, 10 or 15 Gy radiation (n = 6/group). Mice were monitored in Noldus Phenotyper™ cages for 10 baseline days (green), general activity data (blue) were then collected for 10 days post-irradiation and other specific behaviors where characterized using the Mouse Behavioral Module from video from day 8–10 (orange). These behaviors include drinking, grooming, feeding and sleep-like behavior (inlet). (B) Relative general activity levels mapped across 10 days post-treatment when groups were divided into high (5, 10 & 15 Gy; orange) or low (0 & 2 Gy; blue) radiation levels. Activity levels were standardized to produce relative activity values by dividing the 24 h of post-treatment for all 10 days by the average baseline activity levels. Comparisions of high and low radiation levels had significant main effects (time: F(9,234) = 11.686, p < 0.001; radiation dose: F(9,234) = 7.703, p = 0.010) and an interaction between time and level of radiation (F(9,234) = 2.195, p = 0.023). Posthoc tests (tukey) were significant if p < 0.05 (C) Low dose groups remained close to baseline levels (0.0), except for the first two days post-treatment. (D) High dose groups across 10 days post-treatment showed least a 10% decrease in activity by the 6th day post-radiation, with the greatest effects observed in the 10 (dashed line) and 15 (solid line) Gy. E Total sleep levels were significantly higher in the high dose animals than the low dose mice in the last 3 days of monitoring (t(30) = 2.318, p = 0.027). (F) During the inactive period, daytime, mice did not significantly differ in levels of sleep between high and low doses (t(30) = 0.788, p = 0.437). (G) During the active period, nighttime, mice did have significantly more sleep in the high dose group when compared to the low dose group (t(30) = 2.900, p = 0.007). (H) Comparisons in activity level during the active vs inactive periods of 15 Gy at baseline and post-treatment with a significant interaction (F(1,17) = 7.328, p = 0.015). Mice in the high dose groups had significantly less activity during the inactive period (daytime). (I) Twenty-four profile of activity for the low dose group during the baseline and post-treatment were similar. Grey panels indicate the active period, while the white portion of the graph are the inactive period. There was a main effects of time (F(23,299) = 66.808, p < 0.001) but not a main effect of radiation (F(1,13) = 0.178, p = 0.680) or interaction between time and radiation (F(23,299) = 1.620, p = 0.160). j. Twenty-four profile of activity for the high dose group during the baseline and post-treatment were different, with post-radiation showing less activity. Statisitcs showed a significant interaction between radiation and time (F(23,391) = 3.028, p = 0.004), with a main effect of time (F(23,391) = 98.257, p < 0.001) but not for radiation (F(1,17) = 2.952, p = 0.104. Posthoc tests (tukey) were significant if p < 0.05. Significance was defined as p < 0.05 and indicated by *.